Thermoplastic composition

ABSTRACT

A thermoplastic elastomer composition comprising a blend of (A) thermoplastic materials comprising (A1) a polyamide block copolymer and (A2) one or more thermoplastic organic polymers excluding (A1), with (B) a silicone composition comprising (B1) a silicone base comprising (B1a) a diorganopolysiloxane polymer having a viscosity of at least 1000000 mPa·s at 25° C. and an average of at least 2 alkenyl groups per molecule, (B1b) a reinforcing filler in an amount of from 1 to 50% by weight of polymer (B1a), and (B2) an organohydrido silicone compound which contains an average of at least 2 silicon-bonded hydrogen groups per molecule, (C) a hydrosilylation catalyst, which composition may additionally optionally comprise (D) one or more additives; wherein the weight ratio (A):(B) is in the range 50:50 to 95:5, and wherein component B2 and C being present in an amount sufficient to cure said silicone composition B.

This invention relates to thermoplastic elastomers (TPEs) especiallyengineering polymers of high added value used in various sectors, suchas electronics, automobiles or sports, as well as thermoplasticelastomer compositions from which they are manufactured and also to aprocess for forming a vulcanised thermoplastic elastomer composition.

Thermoplastic elastomers (TPEs) are polymeric materials which possessboth plastic and rubbery properties. Whilst TPEs have elastomericmechanical properties, unlike conventional thermoset rubbers, they canbe re-processed at elevated temperatures. This re-process ability is amajor advantage of TPEs over chemically crosslinked rubbers since itallows recycling of fabricated parts and results in a considerablereduction of scrap.

In general, two main types of thermoplastic elastomers are known, blockcopolymer TPEs and simple blend TPEs (physical blends).

Block copolymer TPEs contain

-   -   (i) blocks or segments that are called hard or rigid (i.e.        having a thermoplastic behaviour), typically these have a        melting point or glass transition temperature above ambient        temperature; and    -   (ii) blocks or segments that are called soft which are pliable        or flexible (i.e. having an elastomeric behaviour). which        typically have a low glass transition temperature (Tg) or a        melting point considerably below room temperature.    -   The expression “low glass transition temperature” is understood        to mean a glass transition temperature Tg below 15° C.,        preferably below 0° C., advantageously below −15° C., more        advantageously below −30° C., possibly below −50° C.

In Block copolymer thermoplastic elastomers the hard segments aggregateto form distinct micro phases and act as physical crosslinks for thesoft phase, thereby imparting a rubbery character at room temperature.At elevated temperatures, the hard segments melt or soften and allow thecopolymer to flow and to be processed. The hard blocks are generallybased on polyamides, polyurethanes, polyesters or a mixture of thereof.The soft blocks are generally based on polyethers (PE), polyester andcopolymers or blends thereof. Examples of copolymers with hard blocksand soft blocks include,

-   -   copolymers with polyester blocks and polyether blocks        (copolyetheresters which are often abbreviated to COPE);    -   copolymers with polyurethane blocks and polyether blocks        (thermoplastic polyurethanes, often abbreviated to TPU) and    -   copolymers with polyamide blocks and polyether blocks        (Polyether-Block-Amides often abbreviated to PEBA.).

PEBAs are generally plasticizer-free thermoplastic elastomers which areconsidered as engineering polymers. They make it possible to combine, ina single polymer, unequalled mechanical properties and very goodresistance to thermal or UV aging, as well as low density. They thusmake it possible to produce lightweight components. In particular, atequivalent hardness, they dissipate less energy than other materials,which provides them with very good resistance to dynamic stresses inbending or tension, and they have exceptional properties of elasticspringback. However, it is very difficult to generate soft PEBA typematerials which have low shore A hardness, i.e. <100 without losing manyof the benefits described above. Typically PEBAs are approximately 1:1combinations of hard blocks and soft blocks and any significant increasein the proportion of soft blocks can cause manufacturing issues.

TPEs referred to as simple blends or physical blends can be obtained byuniformly mixing an elastomeric component with a thermoplastic resin.When the elastomeric component is also cross-linked during mixing, athermoplastic elastomer known in the art as a thermoplastic vulcanizate(TPV) results. Since the crosslinked elastomeric phase of a TPV isinsoluble and non-flowable at elevated temperature, TPVs generallyexhibit improved oil and solvent resistance as well as reducedcompression set relative to the simple blends.

Typically, a TPV is formed by a process known as dynamic vulcanization,wherein the elastomer and the thermoplastic matrix are mixed and theelastomer is cured with the aid of a crosslinking agent and/or catalystduring the mixing process. A number of such TPVs are known in the art,including some wherein the crosslinked elastomeric component can be asilicone polymer while the thermoplastic component is an organic,non-silicone polymer (i.e., a thermoplastic silicone vulcanize orTPSiV).

U.S. Pat. No. 6,281,286 describes a high impact strength compositionmade from polyamide homopolymer and silicone gum.

U.S. Pat. No. 6,362,288 describes a method to obtain a thermoplasticsilicone elastomer from compatibilized polyamide resin, silicone gum,filler and compatibilizer (coupling agent, organofunctionaldiorganopolysilane or a siloxane copolymer).

The present invention is seeking to obtain a thermoplastic comprising aPEBA in thermoplastic phase having low hardness, i.e. a Shore A hardnessvalue below 90, alternatively a Shore A hardness value of below 85, andas a further alternative a Shore A hardness value of below 80. In eachof the above said hardness values are obtained in the absence of aplasticizer and/or compatibilizer.

There is provided herein a thermoplastic elastomer compositioncomprising a blend of

(A) thermoplastic materials comprising:

-   -   (A1) a thermoplastic organic polyether block amide copolymer and    -   (A2) one or more thermoplastic organic polymers excluding (A1),        with        (B) a silicone composition comprising:    -   (B1) a silicone base comprising:        -   (B1a) a diorganopolysiloxane polymer having a viscosity of            at least 1000000 mPa·s at 25° C. and an average of at least            2 alkenyl groups per molecule,        -   (B1b) a reinforcing filler in an amount of from 1 to 50% by            weight of polymer (B1a), and    -   (B2) an organohydrido silicone compound which contains an        average of at least 2 silicon-bonded hydrogen groups per        molecule,        (C) a hydrosilylation catalyst,    -   which composition may additionally optionally comprise (D) one        or more additives; wherein the weight ratio (A):(B) is in the        range 50:50 to 95:5, and wherein component B2 and C being        present in an amount sufficient to cure said silicone        composition B.

It has been identified that the cured product resulting from curing theabove provides a material having low hardness, i.e. a Shore A hardnessvalue below 90, alternatively a Shore A hardness value of below 85, andas a further alternative a Shore A hardness value of below 80.Furthermore as can be seen from the above composition these values maybe obtained in the absence of a plasticizer and/or compatibilizer.

One advantage of the present invention is to obtain such low hardness byusing hard (A1) and (A2) as the thermoplastic materials (A) therebylimiting soft block content, and thereby maintaining the physicalproperty benefits expected from having a high hard block content such asthermal and chemical resistance whilst the resulting product is has arelatively low Shore A hardness due to the presence of the siliconecomposition (B).

It was observed that the product of the above composition according tothe invention surprisingly substantially maintains the impact or shockresistance of component (A) which would have been expected in theabsence of component (B).

Advantageously, use of plasticisers and/or compatibilizers is not neededto achieve thermoplastic based silicone block copolymer amide elastomerof the present invention.

For the avoidance of doubt, silanes and siloxanes are compoundscontaining silicon.

-   -   A silane is a compound derived from SiH₄. A silane often        contains at least one Si—C bond. A silane usually contains only        one Si atom.    -   A siloxane is a compound which contains at least one Si—O bond.    -   A polysiloxane contains several Si—O—Si— bonds forming a        polymeric chain, where the repeating unit is —(Si—O)—. An        organopolysiloxane is sometimes called a silicone. An        organopolysiloxane contains repeating —(Si—O)— units where at        least one Si atom bears at least one organic group. “Organic”        means containing at least one carbon atom. An organic group is a        chemical group comprising at least one carbon atom.    -   A polysiloxane comprises terminal groups and pendant groups. A        terminal group is a chemical group located on a Si atom which is        at an end of the polymer chain. A pendant group is a group        located on a Si atom which Si atom is not at the end of the        polymeric chain.    -   A polymer is a compound containing repeating units which units        typically form at least one polymeric chain. A polymer can be a        homopolymer or a copolymer. A homopolymer is a polymer which is        formed from only one type of monomer. A copolymer is a polymer        formed from at least two different monomers. A polymer is called        an organic polymer when the repeating units contain carbon        atoms.

Some polymers are thermoset: once cooled and hardened, these polymersretain their shapes and cannot return to their original form. Otherpolymers are thermoplastics: they can soften upon heating and return totheir original form.

A cross linking reaction is a reaction where two or more molecules, atleast one of them being a polymer, are joined together to harden or curethe polymer. A cross linker is a compound able to produce a crosslinkingreaction of a polymer.

The viscosity values of high viscosity diorganopolysiloxane polymers(e.g. ≥1000000 MPa·s) as required in (B1a) may be measured by using anAR 2000 Rheometer from TA Instruments of New Castle, Del., USA or asuitable Brookfield viscometer with the most appropriate spindle for theviscosity being measured. However, (B1a) may be a silicone gum which isa polymer of high molecular weight with a very high viscosity. A gumwill typically have a viscosity of at least 2000 000 mPas at 25° C. butgenerally has a significantly greater viscosity. Hence, gums are oftencharacterised by their Williams plasticity value in accordance with ASTMD-926-08 given the viscosity becomes very difficult to measure.

There is also provided herein a process for forming a vulcanisedthermoplastic elastomer from the composition above comprising contactingthermoplastic materials (A) with silicone composition (B).

The weight ratio of (A) to (B) is in the range 50:50 to 95:5.

Additional component (D) could be added in composition to further manageinvention properties according specifics needs of end application.

Thermoplastic Materials (A)

Thermoplastic materials (A) may comprise

from 10-90% by weight of (A1) as described herein and90-10% by weight of (A2),Polyamide block copolymer (A1)

Polyamide block copolymer (A1) is based on hard blocks which may bebased on polyamide or a blend of polyamide and polyester polymers. Theseblocks are in particular described in US 2011/0183099. The hard blocksare preferably based on polyamide. The polyamide (abbreviated to PA)blocks may comprise homopolyamides or copolyamides.

The polyamide blocks that can be envisaged in the composition of theinvention are a block copolymer comprising at least one rigid polyamide(homopolyamide or copolyamide) block and at least one flexible block,Copolymers with hard blocks and soft blocks may include,

-   -   COPE;    -   TPU and preferably    -   thermoplastic organic polyether block amide copolymer (which may        hereafter be referred to as PEBA).

In the PEBA the proportion by weight of said at least one rigidpolyamide block represents from 5% to 95%, preferably from 15% to 95%,the proportion by weight of said at least one flexible block representsfrom 5% to 95%, preferably from 5% to 85%, relative to the total weightof copolymer.

Preferably, the number-average molar mass Mn of the polyamide blocks isincluded in the range of from 400 to 20 000 g/mol, preferably from 500to 10 000 g/mol, more preferably from 500 to 3000 g/mol, even morepreferably from 500 to 2000 g/mol based on polystyrene equivalents usingthe method described in ASTM D6474-12.

In the block copolymer the PA blocks may comprise carboxylic acid endgroups, and the term diacid PA is then used, or else they may comprisean amine end group, and the term diamine PA is used. The bonds betweenthe PA blocks and the soft blocks (SB) can therefore be ester bonds orelse amide bonds. The polyamide blocks comprising dicarboxylic chainends originate, for example, from the condensation of polyamideprecursors in the presence of a chain-limiting dicarboxylic acid.

Three types of polyamides may be part of the composition of these PAblocks Products of the condensation of at least one (aliphatic,cycloaliphatic or aromatic) dicarboxylic acid, e.g. those having from 4to 36 carbon atoms, alternatively from 6 to 18 carbon atoms, and one ormore aliphatic, cycloaliphatic or aromatic diamine chosen in particularfrom those having from 2 to 36 carbon atoms, preferably those havingfrom 6 to 12 carbon atoms

Products of the condensation of one or more alpha, omega-aminocarboxylicacids and/or of one or more lactams having from 6 to 12 carbon atoms inthe presence of a dicarboxylic acid having from 4 to 36 carbon atoms orof a diamine. Advantageously, the polyamide blocks of the second typeare of polyamide 11, of polyamide 12 or of polyamide 6.

Polycondensation of at least one alpha, omega-aminocarboxylic acid (orone lactam) with at least one diamine and one dicarboxylic acid. In thiscase, the PA blocks are prepared by polycondensation: of the aliphatic,cycloaliphatic or aromatic diamine(s) having X carbon atoms; of thedicarboxylic acid(s) having Y carbon atoms; and of the comonomer(s) {Z},chosen from lactams and alpha, omega-aminocarboxylic acids having Zcarbon atoms; in the presence of a chain limiter chosen fromdicarboxylic acids or diamines or of an excess of diacid or of diamineused as structural unit. Advantageously, the dicarboxylic acid having Ycarbon atoms is used as chain limiter, said dicarboxylic acid beingintroduced in excess relative to the stoichiometry of the diamine(s).

Products of the condensation of at least two different alpha,omega-aminocarboxylic acids or of at least two different lactams havingfrom 6 to 12 carbon atoms or of a lactam and of an aminocarboxylic acidnot having the same number of carbon atoms, optionally in the presenceof a chain limiter.

Examples of aliphatic diacids, include, for the sake of example,butanedioic acid, adipic acid, suberic acid, azelaic acid, sebacic acid,dodecanedicarboxylic acid, myristic acid, tetradecanedicarboxylic acid,hexadecanedicarboxylic acid, octadecanedicarboxylic acid and dimerizedfatty acids. An Example of a cycloaliphatic diacid is1,4-cyclohexyldicarboxylic acid. Examples of aromatic diacids, mentionmay be made of terephthalic (T), isophthalic acid (I) and the sodium,potassium or lithium salt of 5-sulfoisophthalic acid.

Examples of aliphatic diamines, include tetramethylenediamine,hexamethylenediamine, 1,10-decamethylenediamine, dodecamethylenediamineand trimethylhexamethylenediamine. Examples of cycloaliphatic diamines,include the isomers of bis(4-aminocyclohexyl)methane (BACM or PACM),bis(3-methyl-4-aminocyclohexyl)methane (BMACM or MACM), and2,2-bis(3-methyl-4-aminocyclohexyl)propane (BMACP), isophoronediamine(IPDA), 2,6-bis(amino-methyl)norbornane (BAMN) and piperazine (Pip).

Examples of alpha, omega-aminocarboxylic acids, include aminocaproicacid, 7-aminoheptanoic acid, 11-aminoundecanoic acid and12-aminododecanoic acid. Examples of lactams, include caprolactam,enantholactam and lauryllactam.

Products of (i) above may comprise at least one PA block based on PA4.4, PA 4.6, PA 4.9, PA 4.10, PA 4.12, PA 4.13, PA 4.14, PA 4.16, PA4.18, PA 4.36, PA 6.4, PA 6.6, PA 6.9, PA 6.10, PA 6.12, PA 6.13, PA6.14, PA 6.16, PA 6.18, PA 6.36, PA 9.4, PA 9.6, PA 9.10, PA 9.12, PA9.13, PA 9.14, PA 9.16, PA 9.18, PA 9.36, PA 10.4, PA 10.6, PA 10.9, PA10.10, PA 10.12, PA 10.13, PA 10.14, PA 10.16, PA 10.18, PA 10.36, PA10.T, PA 10.1, PA BMACM.4, PA BMACM.6, PA BMACM.9, PA BMACM.10, PABMACM.12, PA BMACM.13, PA BMACM.14, PA BMACM.16, PA BMACM.18, PABMACM.36, PA PACM.4, PA PACM.6, PA PACM.9, PA PACM.10, PA PACM.12, PAPACM.13, PA PACM.14, PA PACM.16, PA PACM.18, PA PACM.36, PA Pip.4, PAPip.6, PA Pip.9, PA Pip.10, PA Pip.12, PA Pip.13, PA Pip.14, PA Pip.16,PA Pip.18 and/or PA Pip.36, and copolymers thereof.

Alternatively, the polyamide blocks, may be made from the followingpolyamides (copolyamides): PA 6/12 where 6 denotes caprolactam and 12denotes lauryllactam; PA 11/12 where 11 denotes 11-aminoundecanoic acidand 12 denotes lauryllactam; PA 6/11 where 6 denotes caprolactam and 11denotes 11-aminoundecanoic acid; PA 6/6.6 where 6 denotes caprolactamand 6.6 denotes a monomer resulting from the condensation ofhexamethylenediamine with adipic acid. Examples, include PA 10.10/11, PA6.10/11, PA 10.12/11, PA 10.10/11/12, PA 6.10/10.10/11, PA 6.10/6.12/11,PA 6.10/6.12/10.10, PA 11/6.36, PA 11/10.36 and PA 10.10/10.36.

As examples of polyamide blocks, mention may be made of those comprisingat least one of the following molecules: PA-12, PA-11, PA-10,10,PA-6.10, PA-6, PA-6/12, a copolyamide comprising at least one of thefollowing monomers: 11, 5,4, 5,9, 5,10, 5,12, 5,13, 5,14, 5,16, 5,18,5,36, 6,4, 6,9, 6,10, 6,12, 6,13, 6,14, 6,16, 6,18, 6,36, 10,4, 10,9,10,10, 10,12, 10,13, 10,14, 10,16, 10,18, 10,36, 10,T, 12,4, 12,9,12,10, 12,12, 12,13, 12,14, 12,16, 12,18, 12,36, 12,T and blends orcopolymers thereof.

Alternatively, the polyamide blocks, may be made from the followingpolyamides (copolyamides): PA 6/12 where 6 denotes caprolactam and 12denotes lauryllactam; PA 11/12 where 11 denotes 11-aminoundecanoic acidand 12 denotes lauryllactam; PA 6/11 where 6 denotes caprolactam and 11denotes 11-aminoundecanoic acid; PA 6/6.6 where 6 denotes caprolactamand 6.6 denotes a monomer resulting from the condensation ofhexamethylenediamine with adipic acid. Examples, include PA 10.10/11, PA6.10/11, PA 10.12/11, PA 10.10/11/12, PA 6.10/10.10/11, PA 6.10/6.12/11,PA 6.10/6.12/10.10, PA 11/6.36, PA 11/10.36 and PA 10.10/10.36.

As examples of polyamide blocks, mention may be made of those comprisingat least one of the following molecules: PA-12, PA-11, PA-10,10,PA-6,10, PA-6, PA-6/12, a copolyamide comprising at least one of thefollowing monomers: 11, 5,4, 5,9, 5,10, 5,12, 5,13, 5,14, 5,16, 5,18,5,36, 6,4, 6,9, 6,10, 6,12, 6,13, 6,14, 6,16, 6,18, 6,36, 10,4, 10,9,10,10, 10,12, 10,13, 10,14, 10,16, 10,18, 10,36, 10,T, 12,4, 12,9,12,10, 12,12, 12,13, 12,14, 12,16, 12,18, 12,36, 12,T and blends orcopolymers thereof.

Polyamide block copolymer (A1) also comprises soft or flexible blocksthat can be envisaged in the copolymer according to the invention, areunderstood in particular to be those chosen from polyether blocks andpolyester blocks. By way of example, the polyether blocks are chosenfrom poly(ethylene glycol) (PEG), poly(1,2-propylene glycol) (PPG),poly(1,3-propylene glycol) (PO3G), poly(tetramethylene glycol) (PTMG)and copolymers or blends thereof. Preferably, the number-averagemolecular weight Mn of the soft blocks according to the invention iswithin the range extending from 250 to 5000 g/mol, alternatively from250 to 3000 g/mol, alternatively from 500 to 2000 g/mol based onpolystyrene equivalents using the method described in ASTM D6474-12.

According to one preferred embodiment, the PA blocks of the copolymerused in the invention comprise more than 70 mol %, preferably more than80 mol %, preferably more than 90 mol %, preferably 100 mol % of anequimolar combination of at least one cycloaliphatic diamine and of atleast one aliphatic, preferably linear, dicarboxylic acid having from 12to 18 carbon atoms.

Preferably, said at least one copolymer comprises a copolymer havingpolyamide blocks and polyether blocks (PEBA). Advantageously, said PEBAcomprises PA-12/PEG, PA-6/PEG, PA-6/12/PEG, PA-11/PEG, PA-12/PTMG,PA-6/PTMG, PA-6/12/PTMG, PA-11/PTMG, PA-12/PEG/PPG, PA-6/PEG/PPG,PA-6/12/PEG/PPG, PA-11/PEG/PPG, PA-11/PO3G, PA-6,10/PO3G and/orPA-10,10/PO3G.

PEBA copolymers are commercially available such as those sold under thePEBAX® Trade mark by Arkema or those sold under the Vestamid® trade markby Evonik.

Thermoplastic Organic Polymer (A2)

Thermoplastic organic polymer (A2) used herein may be selected from awide variety of alternatives; including for the sake of examplepolyamide resins, long chain synthetic polymers containing amide (i.e.,—C(O)—NH—) linkages along the main polymer chain, polyester resin,thermoplastic resins such as Polycarbonates (PC),Acrylonitrile-Butadiene-Styrene terpolymers (ABS), polystyrene,poly(phenylene oxide) (PPO), polypropylene (PP), thermoplasticpolyolefins (TPO), polyetherimide (PEI), polyketones and compatiblemixtures thereof.

Furthermore, (A2) may also be a block copolymer, thermoplastic elastomerpolymers, such as Polyurethane, Copolyester, Polyolefin Copolymers,Styrene polyolefin block polymer copolymer such as SBS, SEBS, SEPS,SEEPS, SIBS but as previously indicated (A2) cannot be the same as (A1).

(A2) may contain a compatible mixture of any two or more of the above.

Silicone Composition B Silicone Base (B1) Diorganopolysiloxane Polymer(B1a)

The diorganopolysiloxane polymer (B1a) may have a predominantly linearmolecular structure. The diorganopolysiloxane polymer (B1a) can forexample comprise an α,ω-vinyldimethylsiloxy polydimethylsiloxane, anα,ω-vinyldimethylsiloxy copolymer of methylvinylsiloxane anddimethylsiloxane units, and/or an α,ω-trimethylsiloxy copolymer ofmethylvinylsiloxane and dimethylsiloxane units. The diorganopolysiloxanepolymer (B1a) has a viscosity of at least 1000000 mPa·s at 25° C.measured may be measured by using an AR 2000 Rheometer from TAInstruments of New Castle, Del., USA or a suitable Brookfield viscometerwith the most appropriate spindle for the viscosity being measured. Thediorganopolysiloxane polymer (B1a) can if desired be a gum characterisedby Williams plasticity value as measured by ASTM D-926-08 using aWilliams Parallel plate plastimeter given the viscosity values are sohigh they become very difficult to determine with accuracy. Thediorganopolysiloxane polymer (B1a) can if desired be modified with asmall amount of an unreactive silicone such as atrimethylsilyl-terminated polydimethylsiloxane. In one alternative thediorganopolysiloxane polymer (B1a) is a gum.

The alkenyl groups of the diorganopolysiloxane (B1a) can be exemplifiedby vinyl, hexenyl, allyl, butenyl, pentenyl, and heptenyl groups.Silicon-bonded organic groups in diorganopolysiloxane polymer (B1a)other than alkenyl groups may be exemplified by methyl, ethyl, propyl,butyl, pentyl, hexyl, or similar alkyl groups; or phenyl, tolyl, xylyl,or similar aryl groups.

Reinforcing Filler (B1b)

The reinforcing filler (B1b) can for example be silica. The silica canfor example be fumed (pyrogenic) silica, such as that sold by Cabotunder the trade mark Cab-O-Sil MS-75D, or can be precipitated silica.The particle size of the silica is for example in the range 0.5 μm to 20μm, alternatively 1 μm to 10 μm. The silica can be treated silicaproduced for example by treating silica with a silane or with apolysiloxane. The silane or polysiloxane used to treat the silicausually contains hydrophilic groups which bond to the silica surface andaliphatically unsaturated hydrocarbon or hydrocarbonoxy groups and/orSi-bonded hydrogen atoms.

The silica can for example be treated with an alkoxysilane, for examplea silane comprising at least one Si-bonded alkoxy group and at least oneSi-bonded alkenyl group or at least one Si-bonded hydrogen atom. Thealkoxysilane can be a monoalkoxysilane, a dialkoxysilane or atrialkoxysilane containing at least one aliphatically unsaturatedhydrocarbon group such as a vinylalkoxysilane, for examplevinyltrimethoxysilane, vinyltriethoxysilane orvinymethyldimethoxysilane. The Si-bonded alkoxy groups are readilyhydrolysable to silanol groups which bond to the silica surface.

The silica can alternatively be treated with a polysiloxane, for examplean oligomeric organopolysiloxane, containing Si-bonded alkenyl groupsand silanol end groups.

The silica can for example be treated with 2% to 60% by weight based onthe silica of an alkoxysilane containing alkenyl groups or an oligomericorganopolysiloxane containing alkenyl groups.

Organohydrido Silicone Compound (B2)

Organohydrido silicone compound (B2) having at least two Si-bondedhydrogen atoms per molecule can for example be a low molecular weightorganosilicon resin or a short or long chain organosiloxane polymer,which may be linear or cyclic. The Organohydrido silicone compound (B2)preferably has at least 3 silicon-bonded hydrogens per molecule whichare capable of reacting with the alkenyl or other aliphaticallyunsaturated groups of the diorganopolysiloxane polymer (B1a). TheOrganohydrido silicone compound (B2) may for example have the generalformula

wherein R⁴ denotes an alkyl or aryl group having up to 10 carbon atoms,and R³ denotes a group R⁴ or a hydrogen atom, p has a value of from 0 to20, and q has a value of from 1 to 70, and there are at least 2 or 3silicon-bonded hydrogen atoms present per molecule. R4 can for examplebe a lower alkyl group having 1 to 3 carbon atoms, such as a methylgroup. The Organohydrido silicone compound (B2) can for example have aviscosity of from 1 to 150 mPa·s at 25° C., alternatively 2 to 100 mPa·sor 5 to 60 mPa·s at 25° C. The average degree of polymerisation of theorganopolysiloxane (B2) can for example be in the range 30 to 400siloxane units per molecule. Examples of suitable Organohydrido siliconecompound (B2) include trimethylsiloxane end-blockedpolymethylhydrosiloxanes, dimethylhydrosiloxane end-blocked methylhydrosiloxane, dimethylsiloxane methylhydrosiloxane copolymers andtetramethylcyclotetrasiloxane. The Organohydrido silicone compound (B2)may comprise a mixture of more than one of these materials.

The molar ratio of Si—H groups in the Organohydrido silicone compound(B2) to aliphatically unsaturated groups in the diorganopolysiloxanepolymer (B1a) is preferably at least 1:1 and can be up to 8:1 or 10:1.For example the molar ratio of Si—H groups to aliphatically unsaturatedgroups is in the range from 1.5:1 to 5:1.

Hydrosilylation catalyst (C) The hydrosilylation catalyst (C) ispreferably a platinum group metal (Group VIII of the Periodic Table) ora compound thereof. Platinum and/or platinum compounds are preferred,for example finely powdered platinum; a chloroplatinic acid or analcohol solution of a chloroplatinic acid; an olefin complex of achloroplatinic acid; a complex of a chloroplatinic acid and analkenylsiloxane; a platinum-diketone complex; metallic platinum onsilica, alumina, carbon or a similar carrier; or a thermoplastic resinpowder that contains a platinum compound. Catalysts based on otherplatinum group metals can be exemplified by rhodium, ruthenium, iridium,or palladium compounds. For example, these catalysts can be representedby the following formulas: RhCl(PPh₃)₃, RhCl(CO)(PPh₃)₂, Ru₃(CO)₁₂,IrCl(CO)(PPh₃)₂, and Pd(PPh₃)₄ (where Ph stands for a phenyl group).

The catalyst (C) is preferably used in an amount of 0.5 to 100 parts permillion by weight platinum group metal based on the polyorganosiloxanecomposition (B), more preferably 1 to 50 parts per million. Thehydrosilylation catalyst (C) catalyses the reaction of the alkenylgroups of diorganopolysiloxane polymer (B1a) with the Si—H groups ofOrganohydrido silicone compound (B2).

Additives—Component D

Components (D) are present in the thermoplastic elastomer compositionsof the invention to obtain a desired processing or performance propertyfor the thermoplastic elastomer.

Such additional components may for example include softening mineraloils, plasticisers, other mineral fillers (i.e. excluding the (B1b)reinforcing fillers, viscosity modifiers, stabilisers, lubricants,polydimethylsiloxane (PDMS), thermoplastic elastomer and fire resistantadditives, colouring agents such as pigments and/or dyes; effectpigments, such as diffractive pigments; interference pigments, such aspearlescent agents; reflective pigments and mixtures thereof andmixtures of any of the above pigments; UV stabilizers, anti-agingagents, antioxidants, fluidizing agents, anti-abrasion agents,mold-release agents, stabilizers, plasticizers, impact modifiers,surfactants, brighteners, fillers, fibres, waxes, and mixtures thereof,and/or any other additive well known in the field of polymers.

Such component should be used alone or in combination. Addition level ofcomponent (D) should be up to 30 weight % of total composition.Preferably if there is one or more components (D) present the totalcumulative amount of said additives is typically present from 0.01 to20%, preferably from 0.01 to 10%, preferably from 0.01 to 5%, by weightout of the total weight of the composition

Mineral oils are generally petroleum distillates in the C15 to C40range, for example white oil, liquid paraffin or a naphthenic oil. Ifused, the mineral oil can for example be premixed with the thermoplasticorganic polymer (A). The mineral oil can for example be present at 0.5to 20% by weight based on the thermoplastic organic polymer (A).

Plasticizers can be present in combination with or alternatively tomineral oils. Examples of suitable plasticisers include phosphate esterplasticisers such as friaryl phosphate isopropylated, resorcinalbis-(diphenyl phosphate) or phosphate ester sold by Great Lakes ChemicalCorporation under the trade mark Reofos® RDP. Such plasticizers can forexample be used in a range from 0.5 up to 15%.

Examples of other mineral fillers include talc or calcium carbonate.Fillers may be treated to make their surface hydrophobic. Such fillers,if present, are preferably present at a lower level than the reinforcingfiller (B1b) such as silica. Said fillers may be premixed either withthe thermoplastic organic polymer (A) or the silicone base (B1).

Examples of pigments include carbon black and titanium dioxide. Pigmentscan for example be premixed with the thermoplastic organic polymer (A).

A stabiliser can for example be an antioxidant, for example a hinderedphenol antioxidant such astetrakis(methylene(3,5-di-tert-butyl-4-hydroxy-hydrocinnamate)methanesold by BASF under the trade mark ‘Irganox 1010’. Such an antioxidantcan for example be used at 0.05 to 0.5% by weight of the thermoplasticelastomer composition.

A lubricant can for example be a surface lubricating additive to improvethe processability of the thermoplastic elastomer in mouldingoperations. An example of a surface lubricating additive isEthylbutylstearamide sold by CRODA under the trade mark ‘Crodamide-EBS’.A lubricant can for example be used at 0.1 to 2% by weight of thethermoplastic elastomer composition.

Also contemplated within the scope of this invention is the use of fireretardant additives to provide fire retardancy to the compositions ofthis invention. Traditional fire retardants can be used herein and canbe selected from the group consisting of halogenated varieties such aspolydibromostyrene, copolymers of dibromostyrene, polybromostyrene,brominated polystyrene, tetrabromophthalate esters, tetrabromophthalatediol, tetrabromophthalate anhydride, tetrabromobenzoate ester,hexabromocyclododecane, tetrabromobisphenol A, tetrabromobisphenol Abis(2,3-dibromopropyl ether), tetrabromobisphenol A bis(allyl ether),phenoxy-terminated carbonate oligomer of tetrabromobisphenol A,decabromodiphenylethane, decabromodiphenyl oxide,bis-(tribromophenoxyl)ethane, ethane-1,2-bis(pentabromophenyl),tetradecabromodiphenoxybenzene, ethylenebistetrabromophthalimide,ammonium bromide, poly pentabromobenzyl acrylate, brominated epoxypolymer, brominated epoxy oligomer, and brominated epoxies. Other,non-halogen varieties can be selected from such materials as friarylphosphates isopropylated, cresyl diphenyl phosphate, tricresylphosphate, trixylxl phosphate, triphenylphosphate, triaryl phosphatesbutylated, resorcinol bis-(diphenyl phosphate), bisphenol A bis(diphenylphosphate), melamine phosphate, melamine pyrophosphate, melaminepolyphosphate, dimelamine phosphate, melamine, melamine cyanurate,magnesium hydroxide, antimony trioxide, red phosphorous, zinc borate,and zinc stanate. It is known by those skilled in the art with regard tohow much of the fire retardant can be added to give the required effect.Those amounts are also useful herein.

As hereinbefore described there is also provided herein a process forforming a vulcanised thermoplastic elastomer from the thermoplasticelastomer composition described above. By contacting thermoplasticmaterials (A) with silicone composition (B).

The weight ratio of (A) to (B) is in the range 50:50 to 95:5.

Additional component (D) could be added in composition to further manageinvention properties according specifics needs of end application.

The thermoplastic elastomer is produced by contacting the thermoplasticorganic polymer (A), which may be pre-mixed with additives (D) (whenpresent) i.e. =(A)+(D, if present) with silicone composition Bcomprising (B1) a silicone base comprising:

-   (B1a) a diorganopolysiloxane polymer (preferably a gum) having an    average of at least 2 alkenyl groups per molecule,-   (B1b) from 1 to 50% by weight based on the diorganopolysiloxane    polymer (B1a) of a reinforcing filler, and-   (B2) an organohydrido silicone compound which contains an average of    at least 2 silicon-bonded hydrogen groups per molecule,-   (C) a hydrosilylation catalyst.

The above ingredients are generally contacted at elevated temperature,for example a temperature in the range 100° C. to 250° C. A temperaturein the range 160° C. to 240° C., alternatively 180° C. to 220° C., canconveniently be used. Reaction of the alkenyl groups ofdiorganopolysiloxane polymer (B1a) with the Si—H groups of organohydridosilicone compound (B2) proceeds simultaneously with mixing of thesilicone composition (B) with the pre-mixture of (A)+(D, if present),resulting in the production of a vulcanised thermoplastic elastomercomposition.

The ingredients are mixed in any device capable of dispersing thesilicone components uniformly in the thermoplastic organic polymer (A).The pre-mixture of (A)+(D, if present), and the silicone composition (B)can for example be blended in an extruder. The extruder can be auniaxial extruder, a biaxial extruder, or a multiaxial extruder. A twinscrew extruder, particularly one having a length/diameter (L/D) ratioover 40, is generally suitable. The screw speed can for example be 150to 300 rpm The residence time of the pre-mixture of (A)+(D, if present)and silicone base (B1) in an extruder can for example be 30 to 240seconds.

The silicone base can be prepared by premixing the diorganopolysiloxanepolymer (preferably a gum) (B1a) and the reinforcing filler (B1b) beforefeeding the silicone base (B1) to the extruder or other mixing device,or the diorganopolysiloxane polymer gum (B1a) and the reinforcing filler(B1b) can be fed separately to the mixing device. The silicone base (B1)can be mixed with the pre-mixture of (A)+(D, if present) in the initialprocessing section of the extruder. The pre-mixture of (A)+(D, ifpresent) can for example be introduced into the main feed of aco-rotative twin screw extruder operating at a temperature high enoughto melt the thermoplastic organic polymer. The silicone base (B1) can beadded into the already melted olefin polymer phase using for example agear pump. To maintain the quality of working surroundings and avoidside reactions, inert gas flushing or deaeration using a single stageventing or multi-stage venting can be used.

The organohydrido silicone compound (B2) and the hydrosilylationcatalyst (C) can be added in subsequent sections of the extruder.Dynamical cure or vulcanizing of diorganopolysilxane is conducted duringthe mixing stage, typically within the extruder, when both theorganohydrido silicone compound (B2) and the hydrosilylation catalyst(C) have been added to the composition. The order of addition of theorganohydrido silicone compound (B2) and the hydrosilylation catalyst(C) is not critical. However whichever of these components is addedfirst should be well dispersed in the mixture before the other componentis added to initiate dynamic vulcanization. For example theorganohydrido silicone compound (B2) can be added to the compositionafter the pre-mixture of (A)+(D, if present) and the silicone base (B1)have been mixed, and the hydrosilylation catalyst (C) can be addedsubsequently to initiate dynamic vulcanization while continuing mixing.The organohydrido silicone compound (B2) could alternatively be added tothe composition with the silicone base (B1). In a further alternative,the hydrosilylation catalyst (C) can be added to the composition afterthe pre-mixture of (A)+(D, if present) and the silicone base (B1) havebeen mixed, and the organohydrido silicone compound (B2) can be addedsubsequently to initiate dynamic vulcanization while continuing mixing.

Alternative plastic mixing equipment can be used, for example a batchinternal mixer such as a Z-blades mixer or a Banbury mixer. Thecomponents can be mixed in the order described above, allowingsufficient mixing time for the silicone base (B1) and organohydridosilicone compound (B2) to be well dispersed in thermoplasticpolyurethane polymer before the hydrosilylation catalyst is added toinitiate dynamic vulcanization.

The weight ratio (A):(B) of 2 components is always a respective amountof (A) and (B) with a total amount of (A)+(B) of 100.

The weight ratio of the pre-mixture of (A)+(D), if (D) is present to thesilicone composition (B) is generally in the range 50:50 to 95:5. Withinthis range, the level of silica in the silicone composition (B), theweight ratio of the pre-mixture of (A)+(D), if (D) is present to thesilicone composition (B) and the cross-linking density of the siliconecan be varied to give the desired balance of soft touch feel, mechanicalperformance, moisture resistance, chemical resistance against cosmeticsand scratch resistance. The cross-linking density of the silicone can bevaried by varying the diorganopolysiloxane polymer (B1a) used, inparticular with respect to the siloxane chain length between alkenylgroups. A long chain diorganopolysiloxane polymer gum (B1a) having onlytwo terminal alkenyl groups will form a softer thermoplastic elastomer;a diorganopolysiloxane polymer (B1a) which may be a gum having morealkenyl groups or a shorter chain length will form a harderthermoplastic elastomer.

Use

Elastomers resulting from the cure of the above thermoplastic elastomercompositions combine high mechanical performance, scratch resistance andimproved durability with a desirable soft touch and may be used in awide spectrum of applications such as for example:

The thermoplastic elastomers can for example be used for fabricatingparts or components for automotive applications such as gear knobs, seatbelt connectors, interior mats, airbag protective covers, over-mouldedskins for dash boards and armrests; functional automotive parts such asducts such as air ducts, cable insulation, oil hoses and tanks airbagcover skin, steering wheel skin, gear knobs, grip handle, arm rest,interior skin, car mats (such as cup holder, bin, glove box mat), smallknobs, switches, and large automotive parts (large meaning of surfacegreater than 20 cm²) such as glove box panel, dashboard and door panels.

The thermoplastic elastomers can also be used for fabricating parts orcomponents for electronics and appliance applications such as belts,bracelets, soft temple tips, protective covers and wearable electronics;hoses, boots, bellows, gaskets, soft-feel covers, keyboards palm rest,parts and protective covers of laptops and tablet computing devices.

The thermoplastic elastomers can also be used for fabricating parts orcomponents in sporting goods applications elements of soles of footwearfor sprinting, football, rugby, tennis, basket-ball, running, Alpine orNordic skiing, as well as in golf balls, and in many other sportsarticles;

The thermoplastic elastomers can also be used for fabricating parts orcomponents for electronic device parts in portable electronic,electrical, communication, appliances;

The thermoplastic elastomers can also be used for fabricating parts orcomponents in medical device applications notably as catheters,angioplasty balloons, peristaltic bands;

The thermoplastic elastomers can also be used for fabricating wearableitems or parts or components thereof, such as watch bracelets, GPSbracelets, temple tips and nose pads for sun and reading glasses Suchwearable items retain their attributes over prolonged contact with humanskin and various cosmetic chemicals on the skin such as fragrances,moisturizers and creams, and skin exudates such as sweat.

The thermoplastic elastomers can also be used in general rubberapplications requiring durable aesthetics, haptic and ergonomicproperties along with stability and low staining when exposed to mostcommonly used chemicals, as well as high mechanical performances,abrasion and scratch resistance. conveyor belts, as breathable rainwear.Due to its intrinsic elastomeric properties, it can also be used forweather insulation, such as mirror seal, interior and exterior seal. Dueto the combination of scratch resistance, durability performance andelastomeric properties, it can be used for shoes applications.

The thermoplastic elastomers can also be used for fabricating otherapplications such as protective covers; liquid line components and airducts (non-automotive); architectural seals; bottle closures; furniturecomponents; resistant and soft-feel grips for hand held devices;packaging components such as seals, bottles, cans, cups; medical andhygiene devices; cookware parts and accessories;

The thermoplastic elastomer may be extruded, co-extruded,extruded-laminate, calendaring, extruded-calendaring or laminate to forma thermoplastic film, thermoplastic sheet and synthetic leather, withgrain or none grain surfaces. For example it can be applied on textilecreating a laminate forming a synthetic leather product. Co-extrusion orpost processing with a compatible material, thermoplastic, syntheticwoven or non-woven textile can be achieved to form a complex laminate.Co-extrusion or post processing with a non compatible materialthermoplastic, synthetic or natural woven or non-woven textile, to forma complex laminate can be achieved using adequate primer or interfacialmaterial.

Examples of such applications are:

Synthetic leather for automotive application uses such as seat, doorpanel cover, gear knob, arm rests, steering wheels, wheels cover;Synthetic leather for appliance on electronic application such aselectronic devices such as laptops or tablets providing soft touchfeeling;Synthetic leather for sporting goods and footwear applications watchbands or straps for fitness tracking devices;2 K or two-shot injection moulded parts based on overmoulded,coextruded, or back sheet moulded part with the thermoplastic elastomercomposition of this invention and compatible material;2 K or two-shot injection moulded parts based on overmoulded,coextruded, or back sheet moulded part with the thermoplastic elastomercomposition of this invention and non-compatible material plus use ofadequate adhesion promoter or technique to bond these.

The weight ratio (A):(B) of 2 components is always a respective amountof (A) and (B) with a total amount of (A)+(B) of 100.

The weight ratio of the thermoplastic organic polyether block amidecopolymer to the silicone composition (B) is generally in the range50:50 to 95:5. Within this range, the level of silica in the siliconecomposition (B), the weight ratio of the thermoplastic organic polyetherblock amide copolymer to the silicone composition (B) and thecross-linking density of the silicone can be varied to give the desiredbalance of soft touch feel, mechanical performance, moisture resistance,chemical resistance against cosmetics and scratch resistance. Thecross-linking density of the silicone can be varied by varying thediorganopolysiloxane polymer (B1a) e.g. a gum used, in particular withrespect to the siloxane chain length between alkenyl groups. A longchain diorganopolysiloxane gum (B1a) having only two terminal alkenylgroups will form a softer thermoplastic elastomer; adiorganopolysiloxane gum (B1a) having more alkenyl groups or a shorterchain length will form a harder thermoplastic elastomer.

Due to the combination of scratch resistance, durability performance andelastomeric properties, such materials may be used for footwearapplications.

EXAMPLES

The invention is illustrated by the following examples, in which partsand percentages are by weight unless otherwise stated.

The materials used in the Examples were:

-   -   Si-Rubber 1: Uncatalysed Silicone Rubber Base, comprising a        vinyl-terminated diorganopolysilxane gum and silica. The base        has a plasticity value of 360 mm/100 measured using a Williams        Parallel plate plastimeter in accordance with ASTM D-926-08.        Si-Rubber 1 is intended to have a Shore A hardness of 70 upon        cure.    -   Si-Rubber 2: Uncatalysed Silicone Rubber base, comprising a        vinyl-terminated diorganopolysilxane gum and silica. The base        has a plasticity value of 169 mm/100 measured using a Williams        Parallel plate plastimeter in accordance with ASTM D-926-08.        Si-Rubber 2 is intended to have a shore A hardness of 40 upon        cure.    -   A Silicone based catalyst solution containing adequate catalyst        concentration able to cure Si Rubber bases above    -   PEBA 3: thermoplastic organic polyether block amide copolymer of        25 shore D    -   PEBA 1 thermoplastic organic polyether block amide copolymer of        41 shore D    -   TPU 1: Aliphatic TPU Desmopan 85085 DP0063    -   TPU 2: Aromatic TPU Pearlthane 11T85

Thermoplastic elastomers were prepared by mixing of components andvulcanisation was carried out using a twin screw extruder. Theprocessing section was heated in a range from 160° C. up to 240° C. thescrew speed was between 150 and 400 rpm. Si-Rubber 1 or 2 was added toan organic thermoplastic pre-blend within the first sections of theextruder, then the organohydridopolysiloxane cross linker and thecatalyst, which initiates the vulcanization of the silicone compositionwithin the thermoplastic matrix were added. The proportions of materialsare depicted in Table 1 and 3.

Gloss Measurement

Gloss is determined by projecting a beam of light at a fixed intensityand angle onto a surface and measuring the amount of reflected light atan equal but opposite angle.

TABLE 1 PEBA 1 Ex 1 Ex. 2 Ex. 3 Ex. 4 Si-Rubber 1 with adequate curing 020.87 52.8 agent solution and concentration to ensure crosslinking SiRubber 2 with adequate curing 0 21.19 52.98 agent solution andconcentration to ensure crosslinking PEBA 1 100 79.13 78.81 47.82 47.02

Test specimens for mechanical and scratch resistance testing wereprepared by injection moulding. Heating temperature for injectionmoulding was set at 180° C. to 220° C. and mold temperature set at 40°C. The mechanical properties were tested according to internationalstandards as set out in Table 2 below.

TABLE 2 Unit Standard PEBA 1 Ex 1 Ex. 2 Ex. 3 Ex. 4 Hardness ShoreA ISO868 93.4 91.8 90.9 87.2 85.5 Tensile strength at MPa ISO 37 8.5 8.6 8.27.6 8.5 100% of elongation - transversal- 500 mm/min Tensile strength atMPa ISO 37 8.6 9.8 9.7 9.4 10.6 200% of elongation - transversal- 500mm/min Tensile strength at MPa ISO 37 9.3 11.7 11.5 11.1 12.4 300% ofelongation - transversal- 500 mm/min Tensile strength at MPa ISO 37 43.819.5 20.8 15.9 15 break - transversal- 500 mm/min Elongation at % ISO 37905 528 579 544 455 break - transversal- 500 mm/min Tear strength - N/mmISO R 128 112.2 98.3 71.8 69.1 Transversal- 34/B/A 500 mm/min Flexuralmodulus MPa 85 76 63 46 37 Gloss B Internal 34 39 30 13 9

Comparative example (table 2) shows the benefits of present invention inhardness lowering (compared to pure PEBA 1) and moreover flexibilityincrease.

It can be observe that elastomeric performance in present invention aremaintain, with ultimate elongation value over 400%.

It can be observed that present invention is able to manage differentproperties such as flexibility, hardness, elastic properties and glossby using various silicone Si Rubber composition with adequate curingagent solution and concentration to ensure crosslinking, and keep usinga similar PEBA.

TABLE 3 PEBA 3 TPU 1 TPU 2 Ex 1 Ex. 2 Ex. 3 Ex. 4 Si-Rubber 1 with 026.09 26.09 adequate curing agent solution and concentration to ensurecrosslinking Si Rubber 2 with 0 26.49 26.49 adequate curing agentsolution and concentration to ensure crosslinking PEBA 3 100 47.02 47.8247.02 47.82 TPU 1 100 26.49 26.09 TPU 2 100 26.49 26.09

Test specimens for mechanical and scratch resistance testing wereprepared by injection moulding. Heating temperature for injectionmoulding was set at 180° C. to 220° C. and mold temperature set at 40°C. The mechanical properties were tested according to internationalstandards as set out in Table 4 below.

TABLE 4 Unit Standard PEBA 3 TPU 1 TPU 2 Ex 1 Ex. 2 Ex. 3 Ex. 4 HardnessShore ISO 868: 80 85.1 85.8 78.7 79.4 76.2 78.7 A 2003(en) Tensilestrength MPa ISO 37: 4.1 4.1 5.9 5.1 5.4 4.5 4.6 at 100% of 2011(en)elongation - transversal- 500 mm/min Tensile strength MPa ISO 37: 4.3 57.5 7.0 7.1 6.1 5.9 at 200% of 2011(en) elongation - transversal- 500mm/min Tensile strength MPa ISO 37: 4.9 6.1 10.4 8.9 8.9 7.9 7.7 at 300%of 2011(en) elongation - transversal- 500 mm/min Tensile strength MPaISO 37: 22.6 22.1 42.3 13 13.7 15.7 17.6 at break - 2011(en)transversal- 500 mm/min Elongation at % ISO 37: 928 887 573 529.1 555.9544.7 557.5 break - 2011(en) transversal- 500 mm/min Tear strength -N/mm ISO R 87.7 109.9 106.5 73.5 76.9 63.3 65.8 Transversal- 34/B/A 500mm/min Abrasion Mm3 na 65 46 26 30 27 30 resistance, weight loss, GlossB na Internal 57 65 70 1.4 1.4 1.4 1.6

Comparative example (table 4), a silicone free elastomer shows ahardness of 80 shore A (PEBA 3), as silicone based elastomer of presentinvention.

Comparative example in table 4 shows that different composition ofpresent invention helps to increase mechanical performance at 100%, 200%and 300% elongation measured at room temperature comparing to PEBA 3,while maintaining a similar hardness.

Ultimate performance of products based on present invention confirms theelastomeric properties, with ultimate elongation value over 400%.

Another benefits of present invention is the important reduction ofsurface gloss: addition of a silicone phase in the material brings anintrinsic mat effect while pure CoPA is glossy

1. A thermoplastic elastomer composition comprising a blend of (A)thermoplastic materials comprising (A1) a polyamide block copolymer and(A2) one or more thermoplastic organic polymers excluding (A1), with (B)a silicone composition comprising (B1) a silicone base comprising (B1a)a diorganopolysiloxane polymer having a viscosity of at least 1000000mPa·s at 25° C. and an average of at least 2 alkenyl groups permolecule, (B1b) a reinforcing filler in an amount of from 1 to 50% byweight of polymer (B1a), and (B2) an organohydrido silicone compoundwhich contains an average of at least 2 silicon-bonded hydrogen groupsper molecule, (C) a hydrosilylation catalyst, which composition mayadditionally optionally comprise (D) one or more additives; wherein theweight ratio (A):(B) is in the range 50:50 to 95:5, and whereincomponent B2 and C being present in an amount sufficient to cure saidsilicone composition B.
 2. A thermoplastic elastomer compositionaccording to claim 1 wherein the diorganopolysiloxane polymer (B1a) is adiorganopolysiloxane gum.
 3. A thermoplastic elastomer compositionaccording to claim 1 wherein the reinforcing filler (B1b) is silica. 4.A thermoplastic elastomer composition according to claim 3 wherein thesilica reinforcing filler (B1b) is present at from 2 to 20% by weightbased on the diorganopolysiloxane polymer (B1a)
 5. A thermoplasticelastomer composition according to claim 3 wherein the silicareinforcing filler (B1b) is present at from 6 to 20% by weight based onthe diorganopolysiloxane gum (B1a)
 6. A thermoplastic elastomer curedfrom the thermoplastic elastomer composition in accordance with claim 1.7. A part or component for sports equipment, footwear, automotive,appliances, electronics, portable electronic, electrical, communication,and medical applications wherein the part or component comprises thethermoplastic elastomer in accordance with claim
 6. 8. A wearable itemcomprising the thermoplastic elastomer in accordance with claim
 6. 9. Amethod of making a curable item comprising curing the thermoplasticelastomer composition of claim 1 to form the wearable item, wherein thewearable item is intended to be in contact with the wearer's skin whenin use.
 10. A method of making a part, comprising: curing thethermoplastic elastomer composition in accordance with claim 1 in or fora part or component for sports equipment, footwear, automotive,appliances, electronics, portable electronic, electrical, communication,or medical applications
 11. A process for forming a thermoplasticelastomer in accordance with claim 6 comprising mixing (A) thermoplasticmaterials comprising (A1) a polyamide block copolymer and (A2) one ormore thermoplastic organic polymers excluding (A1), (B1) a silicone basecomprising (B1a) a diorganopolysiloxane having a viscosity of at least1000000 mPa·s at 25° C. and an average of at least 2 alkenyl groups permolecule and (B1b) from 1 to 50% by weight based on thediorganopolysiloxane (B1a) of a reinforcing filler, (B2) anorganohydrido silicone compound which contains an average of at least 2silicon-bonded hydrogen groups per molecule and (C) a hydrosilylationcatalyst, the weight ratio of the thermoplastic organic polyether blockamide copolymer to the total weight of the silicone base (B1) and theorganohydrido silicone compound (B2) is in the range 50:50 to 95:5. 12.A process according to claim 11 wherein the thermoplastic organicpolyether block amide copolymer (A), the silicone base (B1), theorganohydrido silicone compound (B2) and the hydrosilylation catalyst(C) are contacted at a temperature in the range 100° C. to 250° C.
 13. Aprocess according to claim 11 wherein the thermoplastic organiccopolymer (A), the silicone base (B1), the organohydrido siliconecompound (B2) and the hydrosilylation catalyst (C) are blended in anextruder.
 14. A process in accordance with claim 11 wherein afterforming said thermoplastic elastomer is extruded, co-extruded,laminated, calendared and/or extruded-calendaring to form athermoplastic film or thermoplastic sheet.